Physics Past Questions and Answers

(a) What is surface tension?
(b) State two methods by which the surface tension of a liquid can be reduced.

(a) Define Young's modulus.
(b) State the physical quantities one has to measure in order to determine the Young's modulus of a wire.

(a) What is the principle upon which the lighting in fluorescent tubes operate?
(b) State two factors on which the colour of light from a fluorescent tube depends.

(a) List two types of waves, apart from light, that can be plane polarised
(b) State two applications of plane polarised light.

(a) State Hooke's law of elasticity
(b) A spiral spring, loaded with a piece of metal, extends by 10.5cm hair. When the metal is fully submerged in water, the spring extends by 6.8cm. Calculate the relative density of the metal. (Assume Hooke's law is obeyed).